1. Field of the Invention
The present invention relates to a microwave oven, and more specifically to a ventilation system for a microwave oven door.
2. Description of the Related Art
Conventional microwave ovens are generally classified into several different types including: tabletop microwave ovens designed to be seated on a table and/or countertop; and a ventilation hood-combined microwave oven designed to be mounted above a oven range—sometimes referred to as Over-The-Range (OTR) microwaves. An OTR microwave includes a ventilation hood type system for exhausting hot air, steam, smoke, etc. generated from the oven range.
In general, microwave ovens are provided with ventilation systems for dissipating heat which may build up during cooking. When the microwave oven is mounted within a wall above a conventional oven, such as in an OTR microwave, the problem of dissipating heat generated during cooking is increased. The heat dissipation problem is especially difficult when the lower oven is in an open-door broiling operation and a microwave oven mounted above the conventional oven is also operating. During this operation, heat rises from the lower conventional oven and can heat the electronic components of the microwave oven which are already in a heated condition due to their normal operation.
It is known in microwave ovens to provide an air circulation system to provide a cooling for various electrical components such as the power transformer and the magnetron and then to direct the air through the cooking cavity to a discharge region. An example of a known system for cooling the electrical compartment of a microwave is shown in U.S. Pat. No. 6,864,472.
In addition to cooling electrical components such as power transformers and magnetrons, it is also known to provide ventilation systems for cooling control elements, such as the electronic control elements associated with the microwave control. U.S. Pat. No. 4,184,945, discloses an air flow system for use in a wall-mount microwave oven and for cooling an electronic component compartment. A front face of the housing is comprised of a movable door and a control panel. A circuit board for holding electronic components is mounted parallel and in a spaced relationship from the control panel. An air passageway is defined in the area between the control panel and the circuit board. An air inlet is disposed adjacent an upper end of the control panel for admitting air into the electrical component compartment and an air outlet is disposed adjacent a lower end of the control panel for allowing air to exit from the electrical component compartment. A blower draws air in through the air inlet, and forces the air through the electrical component compartment and out the air outlet.
In Japanese patent JP8152140, a system is disclosed for cooling a door of a heating cooker, where the door of the heating cooker is hingedly supported to a cabinet. When the door is in a closed state, a lower air path, a spacing inside the door and an upper air path communicates with each other to form a cooling air circulation path.